ADP7105ARDZ

Overview

The ADP7105 is a CMOS low dropout linear regulator operating from 3.3 V to 20 V with up to 500 mA output current. It features 15 µV rms noise, 60 dB PSRR at 10 kHz, and reverse current protection. Dropout voltage is 350 mV at full load. Quiescent current is 900 µA; shutdown current is under 50 µA. Fixed outputs are 1.8 V, 3.3 V, and 5 V; adjustable range is 1.22 V to 19 V. Accuracy is ±0.8% initially, -2% to +1% over temperature. Operating junction temperature is -40°C to +125°C.

Feature Summary

• Low noise performance suitable for sensitive analog circuits
• High power supply rejection ratio across frequency ranges
• Programmable soft start for inrush current control
• Integrated power-good indicator and user-programmable UVLO

Applications

• ADC and DAC circuit regulation
• Precision amplifier power supplies
• High frequency oscillators and clock circuits
• PLL power regulation
• Medical and healthcare equipment

Procurement Notes

Verify the specific package variant (LFCSP or SOIC) and output voltage option against the datasheet ordering guide. Confirm that the component meets RoHS compliance requirements for your assembly process. Ensure input and output capacitor selections adhere to the minimum capacitance and ESR specifications outlined in the data sheet to maintain stability.

Selection Notes

Select based on required output voltage options: fixed 1.8 V, 3.3 V, or 5 V, or adjustable configuration using external resistors. Consider thermal resistance values for the chosen package type when designing PCB layout. Verify that the input voltage range supports the application's maximum supply voltage while maintaining adequate headroom for the desired load current.

Part Context

The ADP7105 belongs to Analog Devices' high-performance LDO family designed for mixed-signal applications. It utilizes an advanced proprietary architecture to achieve excellent transient response with small ceramic capacitors. The device integrates comprehensive protection features including foldback current limiting and thermal overload shutdown for robust system operation.

Replacement Considerations

Consult the official datasheet ordering guide for direct pin-compatible alternatives within the ADP7105 series. Verify electrical parameters such as quiescent current and dropout voltage match application requirements before substitution.

FAQ

How does the SENSE/ADJ pin function differ between fixed and adjustable versions?

In fixed output models, the pin acts as a sense input to measure actual load voltage. In adjustable models, it serves as the adjust input for setting output voltage via an external resistor divider.

What is the purpose of the SS pin?

The SS pin allows connection of an external capacitor to program the startup time, controlling inrush current during power-up sequences.